Looking for guidance from the experienced breeders here. I am hoping to breed my Hanoverian mare this season. She is grey and has one melanoma that showed up when she was 14 years old. What, if any, issues do I need to be aware of regarding a safe pregnancy and foaling? She is my heart horse, and as much as I want a foal of hers to be my last horse, I don’t want to proceed if breeding a mare with melanoma(s) is generally considered a bad idea. I would be very grateful for any input.
[QUOTE=vervachel;6978441]
Looking for guidance from the experienced breeders here. I am hoping to breed my Hanoverian mare this season. She is grey and has one melanoma that showed up when she was 14 years old. What, if any, issues do I need to be aware of regarding a safe pregnancy and foaling? She is my heart horse, and as much as I want a foal of hers to be my last horse, I don’t want to proceed if breeding a mare with melanoma(s) is generally considered a bad idea. I would be very grateful for any input.[/QUOTE]
I don’t know the statistics but breeding can accelerate the cancer, ask your repro vet for the numbers.
Have you had her biopsied or examined for internal melanomas?
This is an open access article published in Feb 2013
Complex Inheritance of Melanoma and Pigmentation of Coat and Skin in Grey Horses
You might contact Dr Jeffrey Phillips re his vaccine work.
[QUOTE=alto;6978467]
I don’t know the statistics but breeding can accelerate the cancer, ask your repro vet for the numbers.
Have you had her biopsied or examined for internal melanomas?
This is an open access article published in Feb 2013
Complex Inheritance of Melanoma and Pigmentation of Coat and Skin in Grey Horses
You might contact Dr Jeffrey Phillips re his vaccine work.[/QUOTE]
(OP if I may side track for a minute!) Thank you for publishing Dr Phillips’ contact info. I have been trying to locate him as I have a horse with a melanoma who needs to be in a study. TN is much closer to Ohio than Florida!!
Back to your regularly scheduled programming…
OP, there is also a study going on at the University of Florida, so you might want to consult with the folks there about melanoma and breeding.
Good luck!
I can answer this one first hand and I wish I had asked this question many many years ago …
I had a lovely grey TB mare that I bred, that had 2 melanoma’s on her throat latch area, maybe the size of very small walnuts. She was 4 when I bred her.
Her pregnancy proceeded normally, but the facility I boarded her at did not attend to her foaling - they slept through the monitor (this was WAY before Mare Stare or other methods we have available now), the foal was stuck in the birth canal and they found him dead in the morning.
I noticed a lot of small melanomas had popped up during the last few months of pregnancy - on her legs, body, none under her tail, and the ones on her throat latch had grown to the size of apricots. This was my first mare that I had ever bred and really didnt think anything of it. Didnt put two and two together at all
Rebred her back to the same stallion and through this pregnancy, the melanoma’s went wild. The ones on her throat were huge, she had literally dozens and dozens springing up all over her body and I prayed she would make it through to foaling. As bad as they were on the outside of her body, I couldnt even imagine what they were like internally
The vet I was using for the 2nd pregnancy told me they cautioned owners with grey horses with melanoma’s to think carefully before breeding them as they could and did go rampant through the pregnancy. I wish my previous vet had told me before I bred her the first time
Long story short - she foaled out a lovely colt, by the time weaning time came around, her body was riddled with hundreds of melanoma’s. I donated her to the University of Guelph where they used her with their vet students for palpating to feel the internal melanoma’s, to study the growth of the external ones and to chart their progress. They tried various treatments on her to see if they could halt their growth to no avail
I received a lovely letter from them when she was 7 years old that they had made the decision to euthanize her as her quality of life was deteriorating and upon a necropsy being performed, all of her internal organs were compromised with melanoma growths as well. They mentioned what a kind mare she was and how the students loved to work with her and everyone was very upset at her passing
So - take it from one who has walked in these shoes before. I would NEVER knowingly breed a grey mare with melanoma’s again unless you are fully prepared to have this outcome in the end
I hope this helps in your decision with your mare
Good lord TC, poor mare 
Thank you for this. I have a lovely grey Connemara cross mare who has had two small melanomas that I’ve contemplated breeding. After this, I won’t.
Yikes TC how horrible!! I often wondered the same thing, if it was like people or not…what about ET for those mares?
It was awful. She was such a sweet and kind mare as well and I often wondered if I hadnt bred her, could she have lived into her teens with those original throat area melanoma’s staying small walnut sized and not progressing at all? And I wish my original vet had said something, knowing this was my first venture into breeding but very possibly they didnt know either. It doesnt seem to be one of those well publicized or well known things - especially back in the early/mid '90’s when I bred this mare
Goodness, that would make me never want to breed a gray mare at all, even if there were no visible melanomas
[QUOTE=TrueColours;6978780]
It was awful. She was such a sweet and kind mare as well and I often wondered if I hadnt bred her, could she have lived into her teens with those original throat area melanoma’s staying small walnut sized and not progressing at all? And I wish my original vet had said something, knowing this was my first venture into breeding but very possibly they didnt know either. It doesnt seem to be one of those well publicized or well known things - especially back in the early/mid '90’s when I bred this mare[/QUOTE]
TC, thank you for sharing your experience. How utterly heartbreaking. This is exactly why I requested information from experienced breeders. My mare had a wonderful foal when she was 6, a perfect pregnancy and a perfect foaling. She is now 17 and has a thumbnail sized melanoma in the area between the rectum and the vagina. I have not had her scoped internally, but it is my understanding that if there is a melanoma showing externally, then there will be internal melanomas. I had come to terms with the thought of the usual risks regarding pregnancy and foaling, but I don’t think I am prepared to risk her becoming a mass of melanomas. Far, far better to lose the stud fee than to lose my girl in that way. As much as it hurts to give up on the dream of having her foal for my last horse, I am sure that someone somewhere will have bred the right Hanoverian filly for me when the time comes to retire my mare. It must have been very painful for you to revisit your experience in order to help me. Thank you for your kindness.
can you do ET? that way you get your foal and your mare doenst have to be pregnant? or would just the act of having a fertilized egg set off the chain reaction?
14 is a more typical age for a grey to begin showing the first signs of melanoma. A horse riddled with Melanoma by age 7 I suspect is somewhat atypical. Still its a terrible story–so sorry TC. Some breeders believe the Homozygous state may have something to do with it—versus one copy of the grey gene and or very late greying individuals. Ive known LOTS of grey horses that lived very long and productive lives competing at the highest levels—though none at the time were actively breeding. I myself lost an aged pony to internal melanomas–so completely understand the concern.
That being said Grey is the preferred color for some breeds–some even believe that among certain Horse Breeds there are breeding lines where grey is desirable as an indicator of certain athletic talents.
Many years ago,I had a beautiful TB mare who I purchased in foal, as a broodmare. She had already had 2 foals at that time.
She had a few small melanomas under her tail when I first bought her, and since I had had a number of grey horses (not broodmares though) with small melanomas, I didn’t really worry.
I didn’t know about any possible connection between melanomas and breeding, nor did my vets mention it to me.
My lovely mare had three more foals, all breedings and foalings easy and uneventful. The melanomas increased gradually as time went by, but I didn’t make the connection between their growth and breeding her, again neither did my vets
I did discuss some drug treatments with one of my vets, but at the time, the treatment was not considered to be effective.
I was assured then that “age would kill the horse before melanomas would”.
At her last repro check following her last foal, the vet did mention that he saw a number of cysts in her reproductive system. At that time he also said that what we see is only a small percentage of what actually exists internally.
He said too that the cancer typically spreads along the spinal cord.
She was still a young and healthy mare, and the vet felt there would be no problem to continue to breed her again, but I felt that she had already done her best for me, and I didn’t want to take any chances with her.
I made the decision to retire her at that time.
It was only later that I found out that there was a correlation between pregnancy and the spread of melanomas.
I feel bad that my ignorance may have made the situation worse for my good mare.
She lived many more years, here on my farm, with the melanomas and tumours (in her throatlatch and behind her girth area, as well as those under her tail growing and increasing.
Nonetheless she continued to eat well, look wonderful and feel fine, enjoying retirement until the good age of 23.
I can’t tell you what to do, OP. I do think it is something you are wise to discuss with a vet who knows about this, so that you can make an informed decision.
Best of luck with your beloved mare, no matter what you decide.
[QUOTE=JB;6978806]
Goodness, that would make me never want to breed a gray mare at all, even if there were no visible melanomas :([/QUOTE]
Me too – but as an Arabian breeder, if I were going to swear off grays, I’d be cut off from a major chunk of my gene pool. I had a gray mare live to be 29, and my next two oldest are 21 and 22. They each had/have a pencil-eraser sized melanoma somewhere (flank and jowl come to mind), and each has had at least two foals – the old mare had five – with no “explosion” of melanomas to be found.
Then again, melanomas may behave differently in Arabians – I have no idea.
I had a friend with a gray mare. She bought her in foal sight unseen, and learned of the melanomas when the mare arrived. After foaling the vet recommended she not be bred again. She was given away with disclosure about the melanomas (which were obvious anyhow) and the warning she should not be bred. We later learned the new owner had bred her, and then found her dead in her pasture one morning just a couple of months into her pregnancy. I don’t know more details than that, except my friend and I both wondered if breeding her had anything to do with it. I think she was in her teens.
[QUOTE=ambar;6979685]
Me too – but as an Arabian breeder, if I were going to swear off grays, I’d be cut off from a major chunk of my gene pool. I had a gray mare live to be 29, and my next two oldest are 21 and 22. They each had/have a pencil-eraser sized melanoma somewhere (flank and jowl come to mind), and each has had at least two foals – the old mare had five – with no “explosion” of melanomas to be found.
Then again, melanomas may behave differently in Arabians – I have no idea.[/QUOTE]
I too am wondering about this. I own a young grey andalusian mare who has had some small melanomas removed from her neck and one in a weird spot on her upper front leg. Not typical locations for melanomas. This is the first time I’ve ever heard warnings about not breeding mares with melanoma. Wouldn’t that eliminate as breeding prospects the majority of grey mares on the planet? I’ll be following this thread closely!
I also wondered about this issue but i have found no research or materai scientifically making the link in horses. (FWIW There is evidence that cimetidine can slow and make tumors regress on some horses and I knew someone that kept their mare on it till she finally died at 28.)
[QUOTE=springer;6979852]
This is the first time I’ve ever heard warnings about not breeding mares with melanoma. Wouldn’t that eliminate as breeding prospects the majority of grey mares on the planet?[/QUOTE]
There wouldn’t be many Lippizans left, that’s for sure.
The problem is that you ha ve no controlled studies to say whether or not those mares would have had developed more melanomas if not pregnant. I have multiple gray geldings with melanomas in my practice and some have had accelerated growth and have died . Certainly pregnancy was not a factor in them. Same with older maiden mares- you just can’t say that pregnancy was the cause. I certainly think that the tendency to getting them is genetic, but not so sure you can blame pregnancy
It’s interesting isn’t it, when you consider that thousands of grey mares are bred annualy without consequence and that 80% of the population of grey horses develop melanoma over the age of fifteen…
Considering that there are varying types of malignent and benign growths I can’t help but wonder if age plays a significant factor in whether or not the age of a mare is an indication as to whether or not the growths are infact more likely to be malignent.
Would having a biopsy taken be of assistance prior to any breeding desicions made? Is the older mare at greater risk than the younger mare? Is there a correlation between the two?
